scholarly journals Efficacy of integrated ultraviolet ultrasonic technologies in the removal of erythromycin- and quinolone-resistant Escherichia coli from domestic wastewater through a laboratory-based experiment

2019 ◽  
Vol 9 (3) ◽  
pp. 571-580
Author(s):  
Owassa Dza Rebecca Annisha ◽  
Zifu Li ◽  
Xiaoqin Zhou ◽  
Ngomah Madgil Don Stenay Junior ◽  
Oscar Omondi Donde

Abstract Bacterial resistance to antibiotics has become a common occurrence especially in areas where antibiotic drugs are widely used. Moreover, the potential effect of antibiotic pollution and the presence of antibiotic-resistant genes (ARGs) on the composition of bacterial communities in the ecosystems continue to degrade the quality of most ecosystems. Despite the use of ultraviolet (UV) radiation and ultrasound (US) technologies in wastewater purification, little is known on their application in the elimination of fecal pathogenic microorganisms such as Escherichia coli. Moreover, their individual and combined potential in the elimination of erythromycin- and quinolone-resistant E. coli is a topic that still requires proper understanding. Therefore, this study was aimed at evaluating the individual and combined/integrative potential of UV radiation and ultrasonic technologies in the removal of erythromycin- and quinolone-resistant E. coli from domestic effluents using a laboratory experimental-based set-up. The results showed that UV radiation experiment was able to significantly eliminate erythromycin- and quinolone-resistant E. coli from the water to a value of 2 log units. Additionally, US technology was equally able to significantly reduce both the erythromycin- and quinolone-resistant E. coli to 2 log units. However, on combining the two technologies, there was further reduction to 1 log unit, hence, pointing to the need for adopting the integrative approach in water purification for increased wastewater purification efficiencies and improved ecosystem and human health.

2021 ◽  
Author(s):  
Shirin Ansari ◽  
James C. Walsh ◽  
Amy L. Bottomley ◽  
Iain G. Duggin ◽  
Catherine Burke ◽  
...  

Rod-shaped bacteria such as Escherichia coli can regulate cell division in response to stress, leading to filamentation, a process where cell growth and DNA replication continues in the absence of division, resulting in elongated cells. The classic example of stress is DNA damage which results in the activation of the SOS response. While the inhibition of cell division during SOS has traditionally been attributed to SulA in E. coli, a previous report suggests that the e14 prophage may also encode an SOS-inducible cell division inhibitor, previously named SfiC. However, the exact gene responsible for this division inhibition has remained unknown for over 35 years. A recent high-throughput over-expression screen in E. coli identified the e14 prophage gene, ymfM, as a potential cell division inhibitor. In this study, we show that the inducible expression of ymfM from a plasmid causes filamentation. We show that this expression of ymfM results in the inhibition of Z ring formation and is independent of the well characterised inhibitors of FtsZ ring assembly in E. coli, SulA, SlmA and MinC. We confirm that ymfM is the gene responsible for the SfiC phenotype as it contributes to the filamentation observed during the SOS response. This function is independent of SulA, highlighting that multiple alternative division inhibition pathways exist during the SOS response. Our data also highlight that our current understanding of cell division regulation during the SOS response is incomplete and raises many questions regarding how many inhibitors there actually are and their purpose for the survival of the organism. Importance: Filamentation is an important biological mechanism which aids in the survival, pathogenesis and antibiotic resistance of bacteria within different environments, including pathogenic bacteria such as uropathogenic Escherichia coli. Here we have identified a bacteriophage-encoded cell division inhibitor which contributes to the filamentation that occurs during the SOS response. Our work highlights that there are multiple pathways that inhibit cell division during stress. Identifying and characterising these pathways is a critical step in understanding survival tactics of bacteria which become important when combating the development of bacterial resistance to antibiotics and their pathogenicity.


2020 ◽  
Vol 8 (8) ◽  
pp. 1165
Author(s):  
Rebecca Veca ◽  
Christian O’Dea ◽  
Jarred Burke ◽  
Eva Hatje ◽  
Anna Kuballa ◽  
...  

Adherent-invasive Escherichia coli (AIEC) strains carry virulence genes (VGs) which are rarely found in strains other than E. coli. These strains are abundantly found in gut mucosa of patients with inflammatory bowel disease (IBD); however, it is not clear whether their prevalence in the gut is affected by the diet of the individual. Therefore, in this study, we compared the population structure of E. coli and the prevalence of AIEC as well as the composition of gut microbiota in fecal samples of healthy participants (n = 61) on either a vegan (n = 34) or omnivore (n = 27) diet to determine whether diet is associated with the presence of AIEC. From each participant, 28 colonies of E. coli were typed using Random Amplified Polymorphic DNA (RAPD)–PCR. A representative of each common type within an individual was tested for the presence of six AIEC-associated VGs. Whole genomic DNA of the gut microbiota was also analyzed for its diversity profiles, utilizing the V5-V6 region of the16S rRNA gene sequence. There were no significant differences in the abundance and diversity of E. coli between the two diet groups. The occurrence of AIEC-associated VGs was also similar among the two groups. However, the diversity of fecal microbiota in vegans was generally higher than omnivores, with Prevotella and Bacteroides dominant in both groups. Whilst 88 microbial taxa were present in both diet groups, 28 taxa were unique to vegans, compared to seven unique taxa in the omnivores. Our results indicate that a vegan diet may not affect the number and diversity of E. coli populations and AIEC prevalence compared to omnivores. The dominance of Prevotella and Bacteroides among omnivores might be accounted for the effect of diet in these groups.


2020 ◽  
Vol 10 (2) ◽  
pp. 276-285 ◽  
Author(s):  
Owassa Dza Rebecca Annisha ◽  
Zifu Li ◽  
Xiaoqin Zhou ◽  
Ngomah Madgil Don Stenay ◽  
Oscar Omondi Donde

Abstract Proper treatment of wastewater is key to the achievement of sustainable environmental management. The use of ultraviolet radiation and ultrasound have continued to be considered as some of the best sustainable practices in wastewater purification. However, despite the suitability of the two emerging techniques in sustainably increasing the purification efficiencies of wastewater, their application has not been fully understood, especially in eliminating faecal pathogenic microorganisms. Moreover, their combined potential in the elimination of Escherichia coli resistant genes from wastewater has not been adequately explored. This study was designed to evaluate the potential of individual and combined/integrated ultraviolet radiation and ultrasonic technologies in the removal of antibiotic-resistant E. coli from domestic effluents. There was a statistical difference in the mean log units of sulfonamide resistant E. coli between the different ultraviolet radiation and ultrasonic dosages (P < 0.05), showing that ultraviolet radiation technology was more effective in the removal of both sulfonamide and tetracycline resistant E. coli from the wastewater. However, the integrated ultraviolet radiation-ultrasonic technique was highly efficient and is recommended in the removal of antibiotic resistant E. coli from wastewater. Nonetheless, further studies also need to be performed to further evaluate the disinfection effectiveness on a different bacteria species under continuous operation.


2003 ◽  
Vol 71 (1) ◽  
pp. 536-540 ◽  
Author(s):  
Melha Mellata ◽  
Maryvonne Dho-Moulin ◽  
Charles M. Dozois ◽  
Roy Curtiss ◽  
Peter K. Brown ◽  
...  

ABSTRACT In chickens, colibacillosis is caused by avian pathogenic Escherichia coli (APEC) via respiratory tract infection. Many virulence factors, including type 1 (F1A) and P (F11) fimbriae, curli, aerobactin, K1 capsule, and temperature-sensitive hemagglutinin (Tsh) and plasmid DNA regions have been associated with APEC. A strong correlation between serum resistance and virulence has been demonstrated, but roles of virulence factors in serum resistance have not been well elucidated. By using mutants of APEC strains TK3, MT78, and χ7122, which belong to serogroups O1, O2, and O78, respectively, we investigated the role of virulence factors in resistance to serum and pathogenicity in chickens. Our results showed that serum resistance is one of the pathogenicity mechanisms of APEC strains. Virulence factors that increased bacterial resistance to serum and colonization of internal organs of infected chickens were O78 lipopolysaccharide of E. coli χ7122 and the K1 capsule of E. coli MT78. In contrast, curli, type 1, and P fimbriae did not appear to contribute to serum resistance. We also showed that the iss gene, which was previously demonstrated to increase resistance to serum in certain E. coli strains, is located on plasmid pAPEC-1 of E. coli χ7122 but does not play a major role in resistance to serum for strain χ7122.


2004 ◽  
Vol 70 (7) ◽  
pp. 4276-4285 ◽  
Author(s):  
Richard L. Whitman ◽  
Meredith B. Nevers ◽  
Ginger C. Korinek ◽  
Muruleedhara N. Byappanahalli

ABSTRACT Studies on solar inactivation of Escherichia coli in freshwater and in situ have been limited. At 63rd St. Beach, Chicago, Ill., factors influencing the daily periodicity of culturable E. coli, particularly insolation, were examined. Water samples for E. coli analysis were collected twice daily between April and September 2000 three times a week along five transects in two depths of water. Hydrometeorological conditions were continuously logged: UV radiation, total insolation, wind speed and direction, wave height, and relative lake level. On 10 days, transects were sampled hourly from 0700 to 1500 h. The effect of sunlight on E. coli inactivation was evaluated with dark and transparent in situ mesocosms and ambient lake water. For the study, the number of E. coli samples collected (n) was 2,676. During sunny days, E. coli counts decreased exponentially with day length and exposure to insolation, but on cloudy days, E. coli inactivation was diminished; the E. coli decay rate was strongly influenced by initial concentration. In situ experiments confirmed that insolation primarily inactivated E. coli; UV radiation only marginally affected E. coli concentration. The relationship between insolation and E. coli density is complicated by relative lake level, wave height, and turbidity, all of which are often products of wind vector. Continuous importation and nighttime replenishment of E. coli were evident. These findings (i) suggest that solar inactivation is an important mechanism for natural reduction of indicator bacteria in large freshwater bodies and (ii) have implications for management strategies of nontidal waters and the use of E. coli as an indicator organism.


2005 ◽  
Vol 51 (12) ◽  
pp. 1027-1037 ◽  
Author(s):  
Richard L Whitman ◽  
Stacey E Byers ◽  
Dawn A Shively ◽  
Donna M Ferguson ◽  
Muruleedhara Byappanahalli

Sarracenia purpurea L., a carnivorous bog plant (also known as the pitcher plant), represents an excellent model of a well-defined, self-contained ecosystem; the individual pitchers of the plant serve as a microhabitat for a variety of micro- and macro-organisms. Previously, fecal indicator bacteria (Escherichia coli and enterococci) were shown as incidental contaminants in pitcher fluid; however, whether their occurrence in pitcher fluid is incidental or common has not been established. The purpose of this study was to investigate the occurrence, distribution, and growth potential of E. coli and enterococci in pitcher plant fluid from a protected bog in northwest Indiana. Escherichia coli and enterococci were recovered in pitcher fluids (n = 43 plants), with mean densities (log CFU mL–1) of 1.28 ± 0.23 and 1.97 ± 0.27, respectively. In vitro experiments showed that E. coli growth in fluid not containing insects or indigenous organisms was directly proportional to the fluid concentration (growth was 10-fold in 24 h in 100% fluid); however, in the presence of other indigenous organisms, E. coli and enterococci were only sustained for 5 days at 26 °C. Pulsed-field gel electrophoresis (PFGE) analysis showed that the plant Enterococcus faecalis isolates were genetically distinct from the human isolates; identical PFGE patterns were observed among plant isolates that fell into one of six clonal groups. These findings suggest that (i) E. coli and enterococci occurrence in pitcher plants is rather common in the bog studied, although their originating source is unclear, and (ii) the pitcher fluid contains adequate nutrients, especially carbon and energy sources, to promote the growth of indicator bacteria; however, under natural conditions, the biotic factors (e.g., competition for nutrients) may restrict their growth.Key words: indicator bacteria, environmental occurrence, microcosm, pitcher plant fluid, temperate bog.


1976 ◽  
Vol 54 (4) ◽  
pp. 301-306 ◽  
Author(s):  
M. G. Burrington ◽  
A. R. Morgan

The Escherichia coli omega protein was first described by Wang (Wang, J.C.: J. Mol. Biol. 55, 523–533 (1971)) as having the ability to relax supercoiled covalently-closed circular DNA by changing the topological winding number, α. We have developed a rapid assay for omega activity which has allowed us to purify the protein to homogeneity. It appears to be an αβ-ype subunit protein with a molecular weight of the intact protein of about 80 000 (determined by gel filtration) and of the individual subunits of 56 000 and 31 000 (sodium dodecyl sulfate polyacrylamide gels). We have confirmed Wang's observation that it only partly relaxes negative supercoils, and is not active on positive supercoils. Its characteristics with respect to pH, salts, temperature and chromatography are described. A method for rapid screening of E. coli for omega mutants is described.


OENO One ◽  
2021 ◽  
Vol 55 (1) ◽  
pp. 45-48
Author(s):  
Mladen Boban ◽  
Nataša Boban ◽  
Marija Tonkić ◽  
Mia Grga ◽  
Ana Marija Milat ◽  
...  

Although antimicrobial properties of wine have been extensively studied, antimicrobial effects of wine in relation to bacterial resistance to medicinal antibiotics have not been examined. Therefore, our aim was to determine whether bacterial resistance to antibiotics can be related to their resistance to red wine as an unspecific antimicrobial medium. The organisms studied were Salmonella enteritidis (ATCC 13076), Escherichia coli (ATCC 25922), and two clinical isolates which exhibited different resistance to antibiotics, ESBL - producing Escherichia coli UR 3612 and Salmonella enteritidis KK 962. The time-kill curves method was used. The minimal incubation time of the bacterial suspension with wine, necessary for prevention of bacterial growth, was 3 and 20 min for E. coli ATCC and ESBL E. coli respectively. This was associated with susceptibility testing in which E. coli ATCC proved highly sensitive in contrast to ESBL-producing E. coli, which exhibited resistance to a spectrum of antimicrobial drugs of different classes regarding their principal mechanism of action. In the case of S. enteritidis strains, they were similar in their susceptibility against test antibiotics and time-kill curves following exposure to wine. Bacterial resistance to wine is closely associated with bacterial resistance to antimicrobial drugs. The exact mechanisms of antimicrobial activity of wine are still a matter of debate. However, wine might be less susceptible to bacterial resistance development and may include mechanisms different from those of medicinal antibiotics. The present study represents an initial contribution to this important subject which has been practically unexplored.


Author(s):  
Dominique Tertigas ◽  
Gemma Barber

Antibiotic resistance is a pressing issue in the medical field today. It is important to understand the development of bacterial resistance to implement effective preventative measures against antibiotic resistant bacteria. This study investigated the rate at which Escherichia coli (E. coli), a common pathogen, developed resistance to streptomycin and doxycycline, as Oz et al. (2014) showed differing levels of resistance in E. coli to these two antibiotics. The development of antibiotic resistance was measured by adding E. coli to 96-well plates in the presence of increasing doses of doxycycline, streptomycin, or a combination treatment. Successive generations were added to the same treatments to see whether they would grow at higher concentrations of antibiotic. The change in minimum inhibitory concentration for streptomycin and doxycycline was determined as the bacteria became increasingly resistant to each antibiotic. The fastest rate of antibiotic resistance was observed for streptomycin, with doxycycline resistance exhibiting a slower rate of development. The rate of resistance development for the combination treatment was the slowest, potentially due to small differences in target domains. Some cross-resistance was also observed. This study provides a small-scale methodological basis and preliminary insight on antibiotic resistance trends for two antibiotic classes and a combination treatment.


2020 ◽  
Vol 2020 ◽  
Author(s):  
Tchimonbié Messikely Anoman ◽  
Aka Niangoran Marie Stéphanie Kouadio ◽  
Dabé Doga ◽  
Konan Samuel Ahoudjo ◽  
Adolphe Zeze

This study examined the distribution of Escherichia coli (E. coli) resistant to eleven antibiotics and possible relationships among physico-chemical parameters and these resistances. It was carried out over two years during four climatic seasons in five lakes of the Yamoussoukro lake system in Côte d'Ivoire. The physicochemical parameters of the lakes studied are temperature, pH, dissolved oxygen (DO), dissolved organic carbon (DOC), turbidity, nitrates, orthophosphates and ammoniacal nitrogen. A total of 744 water samples were collected from five (5) lakes belonging to the lake system, over a two-year period, during four dry and four wet seasons. Escherichia coli loadings were evaluated after isolation on specific chromogenic medium COMPASS ECC Agar and the susceptibility to antibiotics by the agar diffusion method. Physico-chemical parameters were evaluated according to international standards. The physico-chemical results showed that the nutrient contents evolved generally from upstream to downstream of the lake system, independently of the sources of pollution of five lakes of system. However, the lake B, in upstream of the lake system, showed levels of nitrate, orthophosphate and ammoniacal nitrogen often similar to the downstream lakes. This demonstrates a source of chemical pollution in this lake, which flows to lakes D and E, which are themselves subject to other pollution. Bacterial loads and bacterial resistance to antibiotics have strictly evolved from upstream to downstream of the system. Most isolates were resistant to ampicillin (16.46%), tetracycline (12.87%), ciprofloxacin (12.86%) and sulfamethoxazole (10.14%). Antibiotic resistance patterns of E. coli isolates were similar in both years studied, but higher during rainy seasons (GRS and SRS). The spearman rank correlations and the principal component analysis (PCA) revealed significant correlations between bacterial resistance to antibiotics in lakes and water physico-chemical parameters. Turbidity and DOC can help to determine the main resistances in the lake D. Orthophosphates can help to understand the resistance of chloramphenicol and the nitrates can help to understand the resistance of ampicillin in the lake B. Resistance in the lakes A, B and C can be influenced by dissolved oxygen. Overall, this study provided baseline information on bacterial resistance in the lakes of Yamoussoukro in Côte d'Ivoire, showing that these lakes could be reservoirs of antibiotic resistance, potentially dangerous to public health.


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